MapReduce / Hadoop videos and tutorials

Except the official documentation, here's my source of information about Hadoop

- One of the best resources I've seen on the web about Hadoop and the tools it has (hbase, pig, hive): the Cloudera Videos.
- Two lectures from a course from UCBerkeley about MapReduce and Hadoop here and here.
- A free book about MapReduce algorithms from here.
- Blogs:

• Yahoo Hadoop blog.
• HStack
• Twitter and Facebook engineering blogs.

Another very good source of information about the inner workings of Hadoop was Hadoop: The Definitive Guide.